Retrograde cricopharyngeus dysfunction

The condition is characterised by chronic gastrointestinal symptoms relating to excessive gas retention, including abdominal bloating with distension, flatulence, audible gurgling sounds, and chest and abdominal discomfort. R-CPD has a significant detrimental impact on patients' quality of life. == Anatomy and Pathophysiology ==

The cricopharyngeus muscle is the major muscle comprising the upper esophageal sphincter (UES). It is a strap-like, C-shaped muscle at the base of the throat behind the larynx. The UES encircles the proximal (upper) opening of the esophagus. The upper esophageal sphincter has a residual tone that is in fact augmented as it is stretched open. Swallowing of air during eating and drinking is normal. However, as air cannot be absorbed by the gastrointestinal tract it is mostly vented via burping. A transient relaxation of the lower esophageal sphincter allows swallowed air in the stomach to rise into the esophagus, where it triggers a reflex relaxation and opening of the UES. In R-CPD, all steps of this belch reflex occur normally up until the last one; despite gaseous distension of the esophagus, the UES fails to open. It is believed that all the symptoms of R-CPD result from failed expulsion of swallowed air and consequent buildup of gas throughout the entire gastrointestinal tract. == Diagnosis ==

Many patients with R-CPD have suffered from years of delayed diagnosis and misdiagnosis and unsuccessful empiric treatment of gastrointestinal disorders including GERD, aerophagia, gallbladder dysfunction, and IBS. == Treatments ==

The treatment of choice is injection of Botulinum toxin into the cricopharyngeus muscle. The effect of botox is delayed for three days on average and most patients with successful results report the ability to belch by the fifth day after the procedure. For most, the effect lasts beyond the first three to six months of direct Botox effect and is usually a lifelong cure. An alternative, if the botox injection is unsuccessful, is to undergo partial cricopharyngeal myotomy. Method of Injection Presently, there are three described methods by which cricopharyngeal Botox injection can be performed: • The most commonly performed approach is injection via direct (rigid) laryngoscope, under general anesthesia. This is the technique favored by most ENT surgeons. • An injection technique via flexible gastrointestinal endoscopy was pioneered by Australian gastroenterologist Dr. Santosh Sanagapalli. This technique appears to have equivalent high success rates, Side effects of treatment Being related to the temporary effect of the Botulinum toxin, side effects are also temporary and typically resolve without treatment. The most common side effect is difficulty swallowing, which often requires temporary diet modification and altered eating style. Less common side effects include sore throat, difficulty breathing on exertion, voice change, and reflux/regurgitation. Side effects appear to be similar no matter which injection technique is used. == References ==